Hello Azarul,

As a rule (pun intended) the volunteers here often avoid doing homework assignments for students, otherwise what have you learned?

There are MANY websites that will show you how to calculate interest using Excel, and Excel even has built-in functions that will do the work for you (see Excel Help -> Financial Functions for a list of them).

Finally, as volunteers, we try to help others and do so at our own pace. If something is very urgent, there is also a Commercial Services Exchange forum in which you can post a request to be done ASAP for a fee (which would be agreed upon between you and the person choosing to assist).

Thanks, and I hope you complete your project!